A store had 175 cell phones in the month of January. Every month 10% of the cell phones were sold and 10 new cell phones were stocked in the store.

Which recursive function best represents the number of cell phones in the store f(n) after n months?
f(n) = 175 - 0.9 • f(n - 1) + 10, f(0) = 175, n 0
f(n) = 0.1 • f(n - 1) + 10, f(0) = 175, n 0
f(n) = 175 + 0.9 • f(n - 1) + 10, f(0) = 175, n 0
f(n) = 0.9 • f(n - 1) + 10, f(0) = 175, n 0

Question

A store had 175 cell phones in the month of January. Every month 10% of the cell phones were sold and 10 new cell phones were stocked in the store.

Which recursive function best represents the number of cell phones in the store f(n) after n months?
 f(n) = 175 - 0.9 • f(n - 1) + 10, f(0) = 175, n > 0
 f(n) = 0.1 • f(n - 1) + 10, f(0) = 175, n > 0
 f(n) = 175 + 0.9 • f(n - 1) + 10, f(0) = 175, n > 0
 f(n) = 0.9 • f(n - 1) + 10, f(0) = 175, n > 0

anonymous · Answer

You can use process of elimination for this one! It wouldn't be B or D so that leaves you with either A or C. Do you agree ?

anonymous · Answer

Agreed. 
That's the point that I've gotten to, but I can't decide between A and C lol.

anonymous · Answer

Lol so I would say the best answer is A because you would need to subtract at some point because 10% of 175 cell phones are SOLD.

anonymous · Answer

But if that's wrong I would say take it over and try C. lol don't judge me

anonymous · Answer

Lol, thanks(: 
No judgements I promise haha.

anonymous · Answer

Lol inbox me

anonymous · Answer

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